LOW NORMAL ALPHA-1-ANTITRYPSIN SERUM CONCENTRATIONS AND MZ-PHENOTYPE ARE ASSOCIATED WITH BYSSINOSIS AND FAMILIAL ALLERGY IN COTTON MILL WORKERS

Recent studies have shown a close association between byssinosis and a irborne endotoxin concentrations. Endotoxin might induce byssinosis th rough the release of biochemical mediators at the broncheoalveolar sur face. Alpha-1-antitrypsin (alpha-1-A) which neutralizes enzymes releas ed by granulocytes is known to be important. This study evaluates the possible importance of alpha-1-A concentration and the heterozygosity (Pi-S and Pi-Z alleles), in the prevalence of byssinosis and familial allergy. 253 cotton workers were interviewed and clinically studied to identify persons with the cotton lung disease, byssinosis, and atopic disease. Serum was available for alpha-1-A concentration determinatio n in 226 individuals, and for Pi phenotyping in 206. The overall preva lence of byssinosis was 30/226 (13%). In the group with alpha-1-A less than or equal to 35 mu mol l(-1) the prevalence was 5/18 (28%), versu s the prevalence 25/208 (12%) in the group with alpha-1-A > 35 mu mol l(-1) (p < 0.1, Fishers exact test). MZ phenotype was associated with an increased prevalence of byssinosis compared with the MM-group: 3/8 (38%) and 25/187 (13%), p < 0.1, Fishers exact test. An association be tween MZ-phenotype and familial allergy was found: 4/8 (50%) contra 23 /187 (12%), p < 0.05, fishers exact test. In a logistic regression mod el controlling for confounding by endotoxin, tobacco exposure, sex, an d age, the odds ratio for byssinosis in the MZ-phenotype group was sig nificantly elevated 5.8 (1.1-30.3). Odds ratio for familial allergy wa s also significantly elevated in the MZ-group 2.8 (1.3-5.9). The Pi-MZ phenotype is thus associated with familial allergy and may predispose to the development of byssinosis.